There have been so many JFK specials already this month, you may have to be persuaded to tune in to one more. So here goes: This one, from 48 Hours, is the real deal. It’s hosted by Bob Schieffer, who was reporting 50 years ago as John F. Kennedy visited Fort Worth and Dallas, and also includes reflections from fellow CBS veterans Dan Rather and (on tape) Walter Cronkite. Its vintage footage includes rare reports from the local CBS TV station in Dallas, and many pieces that put those four November days in a more fluid, even more frightening perspective. No matter how many JFK specials you’ve seen to date, this one is all but guaranteed to show you something you haven’t seen before.